ENGINE 6-25
refer to Section 6 of the Chassis Overhaul Manual.
Because of the interchangeability and similarity of
many engines, engine sub-assemblies and engine parts,
regardless of which passenger vehicle they are used in,
typical illustrations and procedures are used except
where specific illustrations or procedures are necessary
to clarify the operation. Although illustrations showing
bench operations are used, most single operations, when
not part of a general overhaul, should be performed (if
practical) with the engine in the vehicle.
COMPONENT REPLACEMENT AND ADJUSTMENT
ENGINE ASSEMBLY
Removal
• .1. Drain cooling system and engine oil.
2.
Remove air cleaner and disconnect battery cables at
battery.
3.
Remove hood as outlined in Section 11.
4.
Remove radiator and shroud as outlined in Sec-
tion 13.
5. Remove fan blade and pulley as outlined in Sec-
tion 6K.
6. Disconnect wires at:
• Starter solenoid
• Delcotron
• Temperature switch
• Oil pressure switch
• Coil
7. Disconnect:
• Accelerator linkage at pedal lever.
• Exhaust pipes at manifold flanges.
• Vacuum line to power brake unit at manifold (if
so equipped),
• Power steering pump lines at pump end (if so
equipped).
• Fuel line (from tank) at fuel pump.
• Engine cooler lines (if so equipped).
• Oil pressure gauge line (if so equipped).
8. Raise vehicle and place on jack stands.
9. Remove propeller shaft.
NOTE:
If plug for propeller shaft opening
in transmission is not available, drain
transmission.
10.
Disconnect:
• Shift linkage at transmission.
• Speedometer cable at transmission.
• Transmission cooler lines (if so equipped).
11.
On synchromesh equipped vehicles, disconnect clutch
linkage at cross-shaft then remove cross-shaft en-
gine bracket.
12.
Remove rocker arm covers as outlined, then attach
engine lifting adapter at the proper cylinder head bolt
locations.
13.
Remove front mount bolts.
14.
Attach lifting device and raise engine to take weight
off front mounts, then remove rear mount bolts.
15.
Raise engine to take weight off rear mount, then re-
move crossmember.
NOTE:
On Chevrolets it will be necessary to
remove mount from transmission before cross-
member can be removed.
16.
Remove engine-transmission assembly from vehicle
as a unit.
17.
Remove transmission (and clutch):
Synchromesh Transmission
a. Remove clutch housing cover plate screws.
b.
Remove bolts attaching the clutch housing to en-
gine block then remove transmission and clutch
housing as a unit.
NOTE:
Support the transmission as the last
mounting bolt is removed, and as it is being
pulled away from the engine (to prevent damage
to clutch disc).
c. Remove starter and clutch housing rear cover
plate.
d. Loosen clutch mounting bolts a turn at a time (to
prevent distortion of clutch cover) until the spring
pressure is released. Remove all bolts, clutch
disc and pressure plate assembly.
Automatic
Transmission
a. Lower engine, secured by the hoist, and support
engine on blocks.
b.
Remove starter and converter housing underpan.
c. Remove flywheel-to-converter attaching bolts.
d. Support transmission on blocks.
e. Remove transmission-to-engine mounting bolts.
f. With the hoist attached, remove blocks from the
engine only and slowly guide the engine from the
transmission.
18.
Mount engine in stand.
Installation
1.
Attach lifting device to engine and remove engine
from engine stand.
2.
Install transmission (and clutch):
Synchromesh Transmission
a. Install the clutch on flywheel as outlined in Sec-
tion 7.
b.
Install clutch housing rear cover and starter.
c. Install transmission and clutch housing as out-
lined in Section 7.
d. Install clutch housing cover screws and tighten
securely.
Automatic
Transmissions
a. Position engine adjacent to the transmission and
align the converter with the flywheel.
b.
Bolt transmission to engine, then raise engine and
transmission assembly and install flywheel to
converter attaching bolts.
c. Install converter housing underpan and starter.
3.
Tilt and lower engine and transmission assembly into
the chassis as a unit, guiding engine to align front
mounts with frame supports.
4.
Install front mount bolts and torque to specifications.
5. Raise engine enough to install rear crossmember,
then install crossmember, install rear mount, lower
engine and torque rear mount to specifications.
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE 6-26
6. Remove lifting device and lifting adapter then install
rocker arm covers as outlined.
7.
On synchromesh equipped vehicles, install clutch
cross-shaft engine bracket, then adjust and connect
clutch as outlined in Section 7.
8. Connect:
• Speedometer cable.
• Shift linkage at transmission.
• Transmission cooler lines (if so equipped).
9. Install propeller shaft.
10.
Remove jack stands and lower vehicle.
11.
Connect: \ '
Power steering pump lines (if so equipped).
Vacuum line to power brake unit (if so equipped).
Exhaust pipes at manifold flanges.
Accelerator linkage at pedal lever.
Fuel line at fuel pump.
Engine cooler lines (if so equipped).
Oil pressure gauge lines (if so equipped).
12.
Connect wires at:
Coil
Oil pressure switch
Temperature switch
Delcotron
Starter solenoid
13.
Install pulley, fan blade and fan belt as outlined in
Section 6K.
14.
Install radiator and shroud as outlined in Section 13.
15.
Install and adjust hood as outlined in Section 11.
16.
Connect battery cables.
17.
Fill with coolant, engine oil and transmission oil,
then start engine and check for leaks.
18.
Perform necessary adjustments and install air
cleaner.
INTAKE MANIFOLD
Removal
1.
Drain radiator and remove air cleaner.
2.
Disconnect:
Battery cables at battery.
Upper radiator and heater hose at manifold.
Accelerator linkage at pedal lever.
Fuel line at carburetor. ;
Wires at temperature sending switch and coil
(both sides).
Power brake hose at carburetor base.
Spark advance hose at distributor.
Crankcase ventilation hoses (as required).
3.
Remove distributor cap and mark rotor position with
chalk. Remove distributor clamp and distributor,
then position distributor cap rearward clear of
manifold.
4.
Remove coil.
5.
Remove manifold-to-head attaching bolts, then re^
move manifold, (with carburetor on) from engine and
discard gaskets and seals.
6. If manifold is to be replaced,,transfer:
Carburetor and carburetor mounting studs.
Temperature sending switch.
Water outlet and thermostat (use new gasket).
Heater hose adapter.
Choke coil.
Installation
1.
Clean gasket and seal surfaces of manifold, cylinder
heads and block.
2.
Install manifold end seals on block as shown (fig.
2V).
3.
Install side gaskets on cylinder heads using sealing
compound around water passages (fig. 2V).
4.
Install manifold bolts, and torque to specifications in
the sequence outlined on the Torque Sequence Chart.
5.
Install coil.
6. Install distributor with the rotor pointing at the chalk
mark, then install distributor cap.
NOTE:
If the crankshaft has been rotated while
the distributor was removed, time distributor to
number 1 cylinder as outlined in Section 6Y.
7.
Connect:
Battery cables at battery.
Upper radiator and heater hose at manifold.
Accelerator linkage at pedal lever.
Fuel line at carburetor.
Wires at temperature sending switch and coil
(both sides)!
Power brake hose at carburetor base.
Spark advance hose at distributor.
Crankcase ventilation hoses (as required).
Fill with coolant, start engine, check for leaks and
adjust timing and carburetor idle speed and mixture.
EXHAUST MANIFOLD
Removal
NOTE:
If equipped with "Air Injection Reactor
System", remove air manifold and tubes as out-
lined in Section 6T.
1.
Disconnect battery ground cable.
-
2.
Disconnect and remove Delcotron (as required).
3.
On 396 and 427 cu. in. engines, remove spark plugs
Fig. 2V - Intake Manifold Gasket and Seal Location
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE 6-37
Fig.
27V—Removing Camshaft
4.
Set dial indicator on zero, then rotate the damper
slowly, or attach an auxiliary starter switch and
"bump" the engine over, until the push rod is in the
fully raised position.
CAUTION: The primary distributor lead must
be disconnected from the negative post on the
coil and the ignition switch must be in the on
position. Failure to do this will result in a dam-
aged grounding circuit in the ignition switch.
5.
Compare the total lift recorded from the dial indica-
tor with specifications.
6. Continue to rotate the crankshaft until the indicator
reads zero. This will be a check on the accuracy of
the original indicator reading.
7.
If camshaft readings for all lobes are within specifi-
cations, remove dial indicator assembly.
8. Install and adjust valve mechanism as outlined.
Removal
1.
Remove valve lifters as outlined.
2.
Remove crankshaft front cover as outlined.
3.
Remove grille as outlined in Section 13.
4.
Remove fuel pump push rod as outlined * in Sec-
tion 6M.
5.
Complete camshaft removal as follows:
CAUTION: All camshaft journals are the same
diameter and care must be used in removing
camshaft to avoid damage to bearings.
Remove camshaft sprocket to camshaft bolts then
remove sprocket and timing chain together. Sprocket
is a light fit on camshaft. If sprocket does not come
off easily a light blow on the lower edge of the
sprocket (with a plastic mallet) should dislodge the
sprocket.
Install two 5/16" - 18 x 4" bolts in camshaft bolt
holes then remove camshaft (fig. 27V).
Installation
NOTE: Whenever a new camshaft is installed
CONVERTER
BOLT AREA -
DEPRESSED
SYNCHROMESH
RING
GEAR
TRANS.,
AUTOMATIC
Fig.
28V - Flywheel Installation (Typical)
coat camshaft lobes with Molykote or its
equivalent.
1.
Lubricate camshaft journals with engine oil and in-
stall camshaft.
2.
Install timing chain on camshaft sprocket. Hold the
sprocket vertical with the chain hanging down, and
orient to align marks on camshaft and crankshaft
sprockets. Refer to Figure 20V.
3.
Align dowel in camshaft with dowel in hole in cam-
shaft sprocket then install sprocket on camshaft.
Refer to Figure 25V.
4.
Draw the camshaft sprocket onto camshaft using the
mounting bolts. Torque to specifications.
5.
Lubricate timing chain with engine oil.
6. Install fuel pump push rod as outlined in Section 6M.
7.
Install grille as outlined in Section 13.
8. Install crankcase front cover as outlined.
9. Install valve lifters as outlined.
FLYWHEEL
Removal
With transmission and/or clutch housing and clutch
removed from engine, remove the flywheel.
Installation
1.
Clean the mating surfaces of flywheel and crankshaft
to make certain there are no burrs.
2.
Install flywheel on crankshaft and position to align
dowel hole of crankshaft flange and flywheel (fig.
28V).
NOTE: On Automatic Transmission equipped
engines, the flywheel must be installed with the
flange collar to transmission side (fig. 33V).
ENGINE MOUNTS
Engine mounts (fig. 34V) are the nonr adjustable type
and seldom require service. Broken or deteriorated
mounts should be replaced immediately, because of the
added strain placed on other mounts and drive line
components.
Front Mount Replacement
1.
Remove nut, washer and engine mount through-bolt.
2.
Raise engine to release weight from mount.
3.
Remove mount from engine.
CHEVROLET CHASSIS SERVICE MANUAL
SECTION 6M
ENGINE FUEL
CONTENTS OF THIS SECTION
Page
Carburetors 6M-1 Fuel Pumps .
Air Cleaners 6M-7 Special Tools
Page
6M-10
6M-12
CARBURETORS
INDEX
Page
General Description 6M-1
Service Procedures 6M-1
Preliminary Checks 6M-1
Idle Speed and Mixture Adjustment ........... 6M-1
Fast Idle Adjustment .................. 6M-3
Choke Adjustment 6M-3
Float Adjustment 6M-4
Page
Additional Adjustments 6M-4
Removal 6M-4
Test Before Installation 6M-5
Installation 6M-5
Fuel Filter Maintenance 6M-5
Choke Coil Replacement 6M-5
Throttle Linkage Adjustment . . 6M-6
GENERAL DESCRIPTION
Various carburetors (fig. lc) are used with Chevrolet,
Chevelle, Chevy II, Camaro and Corvette passenger
vehicles. These carburetors are designed to meet the
particular requirements of engines, transmissions and
vehicles, therefore carburetors that look alike are not
always interchangeable. (Refer to carburetor part num-
ber and/or specifications.)
Because many service procedures for the various
carburetors are similar, typical illustrations and pro-
cedures are used except where specific illustrations or
procedures are necessary to clarify the operation.
This section covers removal, installation and adjust-
ments (on engine) of carburetors. Also covered in this
section are maintenance procedures for choke coils,
throttle linkage and fuel filters. For carburetor .over-
haul procedures and additional adjustments (bench), re-
fer to Section 6M of the Overhaul Manual under the
carburetor being serviced.
Specifications for carburetors are located in the back
of this manual.
SERVICE PROCEDURES
Preliminary Checks
1.
Thoroughly warm-up engine. If the engine is cold,
allow to run for at least 15 minutes.
2.
Inspect torque of carburetor to intake manifold bolts
and intake manifold to cylinder head bolts to exclude
the possibility of air leaks.
3.
Inspect manifold heat control valve (if used) for free-
dom of action and correct spring tension.
Idle Speed and Mixture Adjustment (Except Air Injection
Reactor System)
NOTE:
This adjustment should be performed
with engine at operating temperature and park-
ing brake applied.
1.
Remove Air Cleaner.
2.
Connect tachometer and vacuum gauge to engine, then
set hand brake and shift transmission into neutral.
3.
As a preliminary adjustment, turn idle mixture
screws lightly to seat and back out 1-1/2 turns.
CAUTION: Do not turn idle mixture screw
tightly against seat or damage may result.
4.
With engine running (choke wide open) adjust idle
speed screw to specified idle speed, (automatic
transmission in drive, synchronized transmission in
neutral).
5. Adjust idle mixture screw to obtain highest steady
vacuum at specified idle speed.
NOTE:
On air conditioned vehicles, turn air
conditioning to the "on" position and hold the
hot idle compensator valve closed while adjust-
ing idle speed and idle mixture screws.
NOTE:
On Rochester BV carburetors the idle
mixture screw should be turned out 1/4 turn
from the "lean roll" position. The definition
of "lean roll" point is a 20 to 30 rpm drop
in engine speed obtained by leaning the idle
mixture.
6. Repeat Steps 4 and5 as needed for final adjustment.
NOTE:
If necessary, final adjustment of the \
carburetor may be made with the air cleaner
installed.
7. Turn engine off, remove gauges and install air
clearer.
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE FUEL 6M-4
Fig.
3C-Fuel Level Sight Plug
2.
Push hand choke knob in to within 1/8" of instru-
ment panel.
3.
Loosen choke cable clamp at carburetor bracket and
adjust cable through the clip until the choke valve
is wide open.
4.
Tighten cable clamp at carburetor bracket and check
operation of choke valve to ensure full closed and
wide open positions.
5. Install air cleaner.
Float Adjustment
Ho/fey (Model 4150
Center
Inlet & Model 2300)
1.
Remove air cleaner then remove the fuel level sight
plugs (Fig. 3c)
2.
With parking brake on, and transmission in neutral,
start the engine and allow it to idle.
3.
With the car on a level surface, the fuel level should
be on a level with the threads at the bottom of the
sight plug port (plus or minus 1/32 inch).
NOTE:
No float drop adjustment is required
on this carburetor.
4.
If necessary to adjust (either or both bowls), loosen
inlet needle lock screw and turn the adjusting nut
clockwise to lower or counter-clockwise to raise
fuel level, then tighten lock screw.
NOTE:
1/6 turn of adjusting nut equals ap-
proximately 1/16" fuel level change.
5. Allow a minute for fuel level to stabilize then re-
check the level at sight plug.
6. Readjust, if necessary, until proper level is obtained,
then install sight plug and air cleaner.
NOTE:
To assure proper secondary float level
setting it is advisable to accelerate primary
throttles slightly and hand operate secondary
throttle. This assures a stabilized secondary
fuel level.
Additional Adjustments
The following adjustments may be made without re-
moving the carburetor from the engine. For procedure
refer to Section 6M of the Overhaul Manual under the
carburetor being serviced.
Rochester BV
• Float
• Idle Vent
• Choke Rod (Fast Idle)
• Choke Vacuum Break
• Choke Unloader
Rochester 2GV
• Float
• Accelerator Pump
• Idle Vent
• Choke Rod (Fast Idle)
• Choke Vacuum Break
• Choke Unloader
• Secondary Throttle Opening
• Secondary Throttle Lockout
Rochester 4MV
• Float
• Accelerator Pumj)
• Idle Vent
• Air Valve
• Choke Rod
• Choke Vacuum Break
• Choke Unloader
• Air Valve Lockout
• Secondary Opening
• Secondary Lockout
Carter YF
• Float
• Idle Vent
• Choke Rod (Fast Idle)
• Choke Vacuum Break
• Choke Unloader
Holley 4160 and 4150
(Except End
Inlet)
• Float
• Air Vent Valve
• Accelerator Pump
• Choke Vacuum Break
• Choke Unloader
Holley 2300 and 4150
(End
Inlet)
• Air Vent Valve (except 2300)
• Accelerator Pump
• Choke Vacuum Break
• Choke Unloader
Removal
Flooding, stumble on acceleration and other perform-
mance complaints are, in many instances, caused by the
presence of dirt, water, or other foreign matter in the
carburetor. To aid in diagnosing the cause of the com-
plaint, the carburetor should be carefully removed from
the engine without draining the fuel from the bowl.
The contents of the fuel bowl may then be examined for
contamination as the carburetor is disassembled.
1.
Remove air cleaner and gasket.
2.
Disconnect fuel and vacuum lines from carburetor.
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE FUEL 6M-5
3.
Disconnect choke rod or choke cable.
4.
Disconnect accelerator linkage.
5.
If equipped with Automatic transmission, discon-
nect TV linkage.
6. Remove carburetor attaching nuts and/or bolts and
remove carburetor.
Test Before Installation -
It is good shop practice to fill the carburetor bowl
before installing the carburetor. This reduces the strain
on the starting motor and battery and reduces the pos-
sibility of backfiring while attempting to start the engine.
A fuel pump clamped to the bench, a small supply of fuel
and the necessary fittings enable the carburetor to be
filled1 and the operation of the float and'intake needle and
seat to be checked. Operate the throttle several times
and check the discharge from the pump jets before in-
stalling the carburetor.
Installation
1.
Be certain throttle body and intake manifold sealing
surfaces are clean.
2.
Install new carburetor to manifold flange gasket (if
required).
3.
Install carburetor over manifold studs.
4.
Start vacuum and fuel lines at carburetor.
5.
Install attaching nuts and/or bolts and tighten
securely.
6. Tighten fuel and vacuum lines.
7.
Connect and adjust accelerator and TV linkage.
8. Connect choke tube or choke rod.
9. Adjust idle speed and mixture, then install air
cleaner. #
Fuel Filter Maintenance
1.
Disconnect fuel line connection at inlet fuel filter
nut.
2.
Remove inlet fuel filter nut from carburetor with a
1"
box wrench or socket.
3.
Remove filter element and spring (fig. 4c).
Fig. 5C-Choke Coil-L6 Engine
4.
Fig. 4C-Fuel Filter
Check element for restriction by blowing on cone
end, element should allow air to pass freely.
5.
Clean element by washing in solvent and blowing out.
Blow in opposite direction of fuel flow.
NOTE: Element should be replaced if plugged
or if flooding ocpurs. A plugged filter will
result in a loss of engine power or rough (pul-
sating) engine feel, especially at high engine
speeds.
6. Install element spring, then install element in car-
buretor so small section of cone faces out.
7.
Install new gasket on inlet fitting nut then install
nut in carburetor and tighten securely.
8. Install fuel line and tighten connector.
Choke Coil Replacement
L6 Engines (Fig. 5c)
1.
Remove air cleaner then disconnect choke rod upper
clip.
2.
Remove bolts attaching choke coil to manifold, then
remove choke coil and choke rod as an assembly.
3.
Disconnect choke rod from choke coil.
4.
Connect choke rod to new choke coil and install as-
sembly on manifold.
5.
Install bolts and tighten securely.
6. Adjust and connect choke rod as outlined.
7.
Start and warm-up the engine then check operation
of choke and install air cleaner.
V8 Engines (Fig. 6c)
1.
Remove air cleaner then disconnect choke rod upper
clip.
2.
Remove choke coil as follows:
WITH ROCHESTER 2GV CARBURETOR
• Remove the choke coil shield by prying with a
screw driver in the cut out provided then re-
move the choke rod.
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE FUEL
6M-10
the
two
"FILL71 lines
(fig.
6A). Refill whenever
the
level
falls below the lower
<'FILL"
line.
Storing Tool
When
the
tool
is
not used, fully depress
the
inner tube.
This seals
off
the
oil
reservoir from the vent hole
to pre-
vent
oil
loss
if
the tool
is
tipped.
Fig. 6A-Filling Tool with
Oil
FUEL PUMP
INDEX
Page
General Description
. . . . 6M-10
Service Procedures .6M-10
Inspection .6M-10
Page
Test
. . ; 6M-10
Removal
6M-11
Installation
6M-11
GENERAL DESCRIPTION
The fuel pump
(fig. IP)
used
on all
Chevrolet vehicles
covered
in
this manual
are of the
diaphragm type.
The
pumps
are
actuated
by an
eccentric located on
the
engine
camshaft.
On
in-line engines,
the
eccentric actuates
the
rocker arm*
On V-8
engines,
a
push
rod
(located be-
tween
the
camshaft eccentric and fuel pump) actuates
the
pump rocker
arm.
Because
of
design, this pump
is
serviced
as an
assembly only.
Fig.
IP—Fuel Pump (Non-Serviceable)
SERVICE PROCEDURES
Inspection
The fuel pump should
be
checked
to
make sure
the
mounting bolts
and
inlet and outlet connections
are
tight.
Test
Always test pump while
it is
mounted on the engine
and
be sure there
is
gasoline
in
the tank.
The line from
the
tank
to the
pump
is the
suction side
of
the
system and the line from the pump
to the
carbure-
tor
is the
pressure side
of the
system.
A
leak on
the
pressure side, therefore, would
be
made apparent
by
CHEVROLET CHASSIS SERVICE MANUAL
ENGINE FUEL 6M-11
dripping fuel, but a leak on the suction would not be ap-
parent except for its effect of reducing volume of fuel on
the pressure side.
1.
Tighten any loose line connections and look for bends
or kinks in lines.
2.
Disconnect fuel pipe at carburetor. Disconnect dis-
tributor to coil primary wire so that engine can be
cranked without firing. Place suitable container at
end of pipe and crank engine a few revolutions. If
little or no gasoline flows from open end of pipe then
fuel pipe is clogged or pump is inoperative. Before
removing pump disconnect fuel pipe at gas tank and
outlet pipe and blow through them with an air hose
to make sure they are clear. Reconnect pipes and
retest while cranking engine.
CAUTION: Whenever the engine is cranked re-
motely at the starter, with a special jumper
cable or other means, the primary distributor
lead must be disconnected from the negative
post on the coil and the ignition switch must be
in the "ON" position. Failure to do this will
result in a damaged grounding circuit in the
ignition switch.
3.
If fuel flows from pump in good volume from pipe
at carburetor, check fuel delivery pressure to be
certain that pump is operating withint specified limits
as follows:
a. Attach a fuel pump pressure test gauge to dis-
connect end of pump to carburetor pipe.
b.
Run engine at approximately 450-1,000 rpm (on
gasoline in carburetor bowl) and note reading on
pressure gauge.
c. If pump is operating properly the pressure will
be within specifications and will remain constant
at speeds between 450-1,000 rpm. If pressure
is too low, too high, or varies materially at dif-
ferent speeds, the pump should be replaced.
Removal
1.
Disconnect fuel inlet and outlet pipes at fuel pump.
Fig.
2P-Installing 283, 327, 350 V8 Engine Fuel Pump
2.
Remove fuel pump mounting bolts and remove pump
and gasket.
3.
On V8 engines; if push rod is to be removed, remove
pipe plug then remove push rod (396 and 427 cu. in.
engines), remove fuel pump adapter and gasket then
remove push rod (283 and 327 cu. in. engines).
4.
If a new fuel pump is to be installed, transfer
fittings.
Installation
1.
On V8 engines; if removed, install fuel pump push
rod and pipe fitting or fuel pump adapter. Use.
gasket sealer on gasket or pipe fitting.
2.
Install fuel pump using a new gasket and tighten
securely. Use sealer on fuel pump mounting bolt
threads.
NOTE:
On V8 engines, a pair of mechanical
fingers may be used to hold fuel pump push rod
up while installing fuel pump (fig. 2P).
3.
Connect fuel pipes to pump.
4.
Start engine and check for leaks.
CHEVROLET CHASSIS SERVICE MANUAL